Circuit interrupter



May 14, 1957 J. B. M NEILL ET AL CIRCUIT INTERRUPTER Filed Feb. 26, 19533 Sheets-Sheet 1 Fig.9.

INVENTORS John B.MacNeillond Fritz E.Florschufz.

WITNESSES:

May 14, 1957 J. B. M ONEILL ETAL 2,792,477

CIRCUIT INTERRUPTEZR Filed Feb. 26, 1953 3 Sheets-Sheet 2 5| 20 Ho H 3l2 l5 l3 l9 I1 '6 I I9 I I Q '9 I E I I I I I c E Q WITNESSES:

INVENTORS John B.MocNeil| 0nd Fritz E.Flors chutz.

May 14, 1957 J. B. M NElLL ETAL 2,792,477

CIRCUIT INTERRUPTER Filed Feb. 26, 1953 3 Sheets-Sheet 3 J Fig.6.

Flg 5 \211 Fig.7.

wnnssszs: INVENTORS John B.M0cNeiH0nd {4777/ Fritz E.Florschutz.

United States Patent This invention relates to circuit-interrupter-s ingeneral, and more particularly to circuit-interrupter tank constructionsfor relatively high-voltage circuit interrupters.

In U. S. patent application Serial No. 174,107, filed July 15, 1950, nowU. S. Patent 2,693,519, issued November 2, 1954 to Benjamin P. Baker andWinthrop M.

eeds, and in U. S. patent application Serial No. 174,012, filed July 15,1950, now U. S. Patent 2,743,337, issued April 24, 1956, to Fritz E.Florschutz and Wayne S. Aspey, both said applications being assigned tothe assignee of the instant application, there are disclosed and claimedcircuit-interrupter tank constructions of novel configuration utilizinga minimum quantity of liquid, such as oil. In liquid-break circuitinterrupters, the liquid, such as oil, must be removed periodically fromthe circuit-interrupter tanks, the extinguishing units inspected afterthe tanks have been emptied, and necessary filtering and reclaimingoperations performed upon the removed oil prior to its replacementwithin the circuitinterrupter tanks. Any steps taken in the direction ofdiminishingthe liquid content of the circuit-interrupter tanks withoutdecreasing necessary electrical clearances are steps taken in the rightdirection, and the aforesaid applications are concerned with tankconstructions utilizing a minimum liquid content without, however,creating a hazardous condition by decreasing electrical clearances belowthe requisite level.

It is an object of the present invention to further improve upon thetank constructions disclosed in the aforesaid two applications byproviding a construction which is cheaper to manufacture, more pleasingin appearance, and at the same time being rugged and having therequisite mechanical strength under the high-pressure conditionsencountered during-the interruption of high-power circuits.

Another object is to provide an improved tank construction in which theaccurate plumbing is easily obtained prior to mounting the leg fixturesto the tank.

Another object is to provide an improved tank construction involving aminimum of liquid content.

A further object is to provide an improved method of manufacturing acircuit-interrupter tank so that the burnofl edges will be in a singlevertical and accurate plane.

Further objects and advantages will readily become apparent upon readingthe following specification, taken in conjunction with the drawings, inwhich:

Figure 1 is a side elevational View of a circuit interrupter embodyingour improved tank construction with the terminal bushings partly brokenaway;

Fig. 2 is an end elevational view of the tank shown in Fig. 1;

Fig. 3 is an enlarged vertical sectional view taken through the tank ofFigs. 1 and 2, showing the interior construction including a pair ofarc-extinguishing units, the contact structure being shown in theclosed-circuit position;

Fig. 4 is a fragmentary sectional view taken along ICE 2 the line IV-IVof Fig. 3 illustrating the lift rod linkage in the closed-circuitposition thereof;

Fig. 5 is a side elevational view of one of the shapes, or tank halves,utilized in the present invention;

Fig. 6 is a top plan view of the shape of Fig. 5;

Fig. 7 is a vertical sectional view through the shape of Fig. 5, takenalong the line VII-VII thereof;

Fig. 8 is an enlarged sectional view through one of the flat spots shownin the shape of Fig. 5 taken along the line VlII-VIII thereof; and

Fig. 9 is a somewhat diagrammatic view of the method of performing theburnolf operation of a tank half.

Referring to the drawings, and more particularly to Figs. 1 and 2thereof, there is shown a circuit interrupter 1, generally of thehigh-voltage type including a pair of terminal bushings 2, 3, preferablyof the condenser type, which extend downwardly within the tank 4 in amanner more clearly shown in Fig. 3 of the drawings.

Disposed at the lower interior ends of the terminal bushings 2, 3 are apair of serially related arc-extinguishing units, generally designatedby the reference character 6. These units 6 may be of the type set outin the U. S. patent application, Serial No. 311,766, filed September 26,1952, now U. S. Patent 2,760,032, issued August 21, 1956, to Benjamin P.Baker and George B. Cushing, and assigned to the assignee of the instantapplication. Generally the units 6 are of the type which establish apressure-genera-ting arc and a serially related interrupting arc, withthe pressure-generating arc forcing liquid, such as oil, under pressuretoward the interrupting arc to effect the latters extinction. Thecontact structure is such as to establish the two breaks of each unit 6substantially simultaneously. The particular construction of the units 6is not important to an understanding of the present invention;consequently, a description of their details is not given, and referencemay be had to the aforesaid application, Serial No. 311,766 for anyfurther description of their operation that might be desired.

As indicated in Fig. 3, the units 6 are electrically interconnected andactuated by a conducting cross-bar, or bridging member 7, which isactuated vertically in a reciprocal manner by an insulating lift rod 8.The lift rod 8 is operated by a lift-rod linkage, generally designatedby the reference character 10, and more clearly shown in Fig. 4 of thedrawings. With reference to Figs. 3 and 4 it will be observed that a rod11 (Fig. 1) mechanically interconnects the several poles of the circuitinterrupter, only one pole being shown in Figs. 13. As well understoodby those skilled in the art, for interrupting a three-phase electricalcircuit, three such poles, or circuit interrupters 1, are arranged uponthe same platform and are electrically and mechanically interconnectedso that they will open and close simultaneously.

The operating rod 11 shown in Fig. 1 extends across the tops of all ofthe circuit interrupters 1 (only one being illustrated) and serves toactuate them simultaneously. As indicated in Fig. 3, the operating rod11 has bifurcated portions 11a, through which pass pivot pins 12 whichserve to interconnect the rod 11 with one or more crank arms. 13. Eachcrank arm 13 has its lower end fixedly secured, or clamped, to a shaft14, the latter extending through the two side plates 15, 16 of a tanktop assembly 17. Generally the tank top assembly 17 includes a pair offlange plate assemblies 19 and a lever box 20. Each flange plateassembly 19 forms a support for its respective terminal bushing 2, 3,and the two flange plate assemblies 19 and the lever-box 20 are weldedtogether initially and positioned as a unit within the top of the tank4, as more clearly describe; hereinafter.

As shown in Fig. 4, clockwise rotation of the shaft 14, as caused by theconnecting rod 11, will cause corresponding clockwise rotation of thetoggle lever 22, the latter being biased in said direction by a toggleaccelerating spring 23. Clockwise rotation of the toggle lever 22 willcause motion of the toggle link 24 to cause clockwise rotation of togglelever 25, the lower end of which is mounted on a stationary pin 26. Thepin 26 is mounted between the two side plates 15, 16 of the lever box20. Cooperating with the toggle lever 25 is a triangularly-shaped togglelink 27, one end of which is pivotally connected to a guide link 28, theupper end of which is pivotally mounted on a stationary pivot 29. Thetoggle link 27 is also pivotally connected to the upper end of theinsulating lift rod 8 as shown in Fig. 4 to effect actuation of thesame. counterclockwise rotation of the shaft 14, when the interrupter isin the open circuit position (not shown) will cause straightening of thetoggle 18 comprising the toggle lever 25 and the toggle link 27, whichaction, in turn, will be accompanied by resetting of the toggle 30including the toggle link 24 and the toggle lever 22 against the biasingaction exerted by the toggle accelerating spring 23.

Thus, opening and closing operations of the bridging member 7 areeffected by actuation of the lift rod linkage 10, in turn caused byhorizontal reciprocal movement of the operating rod 11 across theseveral interrupters 1, and effected by any suitable pneumatic orelectrical mechanism forming no part of our invention.

One feature of our invention is particularly concerned with theconstruction of the tank 4 in an economical manner, and with the resultof such fabrication being a strong and rigid tank capable ofwithstanding high internal pressure. We construct the tank 4 from twotank half shapes, generally designated by the reference character 31 inFigs. -7. Each shape 31 is formed from a blank of sheet metal. In aparticular commercial application, the shape 31 is formed from one-halfinch steel plate. The shape results from pressing the original blankinto a die, and forming or pressing the blank into the configurationshown in Figs. 5-7 of the drawings.

The resulting shape or dished member 31 forms one half of the circuitbreaker tank 4. The remaining half is formed in a similar operation in asingle die, and the two shapes 31 are welded together along theirperipheral edges with the upper end of the tank 4 left open for theinsertion therein of the tank top assembly 17. It will be observed thatthree flat spots 32 are formed in the side of the dished member 31 bythe die. These three flat spots 32, the configuration of which ismoreclearly shown in Fig. 8, form a support for a three-legged toolsupport 33, more clearly shown in Fig. 9 of the drawings. The toolsupport 33 includes a plate 34 having three legs 35, the lower ends ofwhich rest upon the three flat spots 32. Disposed upon the plate 34 is aguide ring 36 against which bears an acetylene burnoif torch 37. Thetorch 37 may be moved about the guide ring 36 by a motor, or it may bemoved manually. The

guide ring 36 insures that the tip 38 of the torch 37 will be apredetermined fixed distance from the periphery 39 of the shape 31 afterit comes from the die. If desired, a water nozzle may follow in the wakeof the burning action of the torch 37 to minimize warpage due to theburnoff heat.

By having the three flat spots 32 provided on the die, and formed in theside of the shape 31, there is assurance that the burnoif operation willtake place ina single plane, which eventually will be the vertical seamof the finished tank 4. Moreover, the three flat spots 32 pro vide adesirable means of supporting the shape 31 by pillars 41) from a base 41during the burnofi operation.

Not only does the die form the fiat spots32, but also it forms twoplumb-line marks 43 (Fig. 5) alongthe center line 44 of the shape 31.Thus, after the burnoft operation and following welding of the-twosides, or

halves, 31 together, it is possible to set the tank up so that the seams45 (Fig. 2) are vertical and the plumbline marks 43 (Fig. 5) are alsoarranged to be vertical, so that the leg supports 46 of the tank 4 maythen be placed in the proper position and welded to the lower portion ofthe tank 4.

It will be apparent from the foregoing operations that the tank 4 ismounted vertically with respect to two of its axes prior to securing thelegs 46 in place. One axis is determined by the vertical seams 45 (Fig.2) resulting from welding the two shapes 31 together. The other axis isdetermined by an alignment of the two plumb line marks 43 (Fig. 5)formed on the shape 31 while the latter is in the die. Thus, the tank 4is positioned in a true and accurate vertical alignment before the legs45 are welded into place.

Referring to Fig. 7, it will be noted that at the upper open end of eachshape 31 there is provided a short vertical side-wall portion 48, whichin one particular instance was three and one-fourth inches long. Inother words, the entire open periphery 49 of the shape 31 is formed withthe walls thereof vertical. This has the advantage that following thewelding of the two shapes 31 together, the tank top assembly 17 (Fig. 3)may be placed interiorly within the open upper end of the tank 4, andlowered to a point where the center-line of the shaft 14 is a fixeddistance D from the base plates 50 welded to the lower ends of the legs46. This has the advantage that the operating rod 11 may be maintainedhorizontally in its passage through the housings 51 (Fig. 3) of theseveral tank top assemblies 17. When the tank top assembly 17 has beenmoved vertically within the side-wall portion 4-8 so that thecenter-line of the shaft 14 is at the predetermined distance D from thebase plates 50, the sides of the tank top assembly may then be welded tothe inner wall of the tank 4. The foregoing construction means that acertain vertical adjustment of the tank top assembly 17 is possiblewithoutunnecessarily increasing the weld gap between the tank topassembly 17 and the inner Walls of the tank 4.

From the foregoing description it is apparent that we have provided arugged and strong circuit interrupter tank formed from a pair of matingtank halves welded together, each half being initially burned from asteel or metal plate, and subsequently preformed to the desired shape ina die. As a practical matter in using only a single die it may benecessary to press the blank only partially into the die, remove theblank and reheat it. It may then be replaced in the die and furtherpressing take place. Actually the blank may be formed by three pressingoperations before it assumes the desired configuration. The die not onlyprovides the flat spots 32 but also forms the plumb-line scoring marks43.

The foregoing description shows how we have utilized the flat spots 32in conjunction with a suitable threelegged tool support 33 to provide aburnofi operation along a single accurate and predetermined plane.

It will be noted that with our, improved tank configuration the width Wof the top of the tank 4, as viewed in Fig. 3, is greater than the widthL of the tank 4 in Fig. 3 adjacent the mid-portion of the tank 4. Thisis indicated by the lateral distance S in Fig. l, and serves to provideadequate mounting space for the current transformers 52, which controlthe relaying operations. By having the width L of the mid-portion of thetank 4 less than that of the top of the tank 4, as viewed in Fig. 3, theliquid content is further decreased over that set out in the first twomentioned applications, and there fore facilitates reclaiming operationsof the oil.

From an overall standpoint, however, it may be stated that generally theentire length of the side seams 45 (Fig. 2) are generally parallel toeach other when the tank 4 is viewed in side elevation as shown in Fig.1.

Viewing Fig. 2, .it will be noticed that the thickness t ,atthe top ofthe tank 4 is less than the thickness T adjacent the mid-portion of thetank. This fact further minimizes the liquid content of the tank 4.

Viewing Fig. 6, it will be apparent that horizontal sections takenthrough the tank 4 are of oval shape.

From the foregoing description it is apparent that the tank 4 is moreeconomically manufactured, the fabrication time is reduced, the resultis stronger and more rugged than tank constructions heretofore known inthe art and the accurate alignment of the legs 46 and the verticalpositioning of the tank top assembly has been expedited.

Although we have shown and described a specific structure and method offorming the same, it is to be clearly understood that the same weremerely for the purpose of illustration, and that changes andmodifications may readily be made therein by those skilled in the artwithout departing from the spirit and scope of the invention.

We claim as our invention:

1. The combination in a circuit interrupter tank of a pair ofcooperating metallic dished members open at one end and having meetingedges at their sides and along a curved line at the other end, the sidesof each dished member being generally parallel to each other, and meanssecuring the meeting edges of two dished members together along theirsides and along the curved line at said other end.

2. The combination in a circuit interrupter tank of a pair ofcooperating metallic dished members open at one end, each dished memberhaving generally parallel sides, the two dished members being joineddirectly to each other along substantially the whole of their periphery,and a tank top assembly enclosing the open ends of the dished members.

3. A circuit interrupter including a tank, a pair of terminal bushingsextending into the tank adjacent the top of the tank, a pair ofarc-extinguishing units carried by the interior ends of the terminalbushings, horizontal sections taken through the tank being of ovalshape, and the width of the top of the tank taken in the plane passingthrough the two terminal bushings being greater than the width of thetank in said plane adjacent the mid-portion of the tank.

4. A circuit interrupter including a tank, the tank including a pair ofopen-ended dished members, means securing the two dished memberstogether along a substantial portion of their periphery, the open endsof the dished members having vertical side portions at least for a shortdistance, a tank-top assembly fitting within the open end of the tank atthe vertical side portions, the arrangement permitting the tank-topassembly to be positioned a predetermined distance from the bottom ofthe tank without increasing the weld gap between the tank-top assemblyand the inner walls of the tank.

5. A circuit interrupter including a tank, a pair of terminal bushingsextending into the tank adjacent the top of the tank, a pair ofarc-extinguishing units carried by the interior ends of the terminalbushings, horizontal sections taken through the tank being of ovalshape, and the width of the top of the tank taken in the plane passingthrough the two terminal bushings being as wide as at the portion of thetank at which the extinguishing units are disposed.

6. A circuit interrupter tank having an upper open end portion, the openend portion having a short length of vertical side walls, a tank topassembly fitting within the open end portion, and the constructionpermitting the tank top assembly to be positioned vertically at theplace desired with a constant weld gap.

7. A circuit interrupter including a tank, arc-extinguishing meansdisposed Within the tank, the two sides of the tank including two formeddished pieces secured together, each dished piece having a roundedbottom and generally parallel side portions with the edges of the side 6portions and the bottom being in a single plane, and each piece beingmore dished adjacent its bottom than near its top so that the thicknessof the top of the tank is less than the thickness of the tank adjacentthe mid-portion thereof.

8. A circuit interrupter including an upstanding tank, a pair ofterminal bushings diverging away from each other in an upward directionand extending within the tank at the upper end thereof,arc-extinguishing means disposed interiorly within the tank andassociated with the interior ends of the terminal bushings, said tankincluding a pair of cooperating Whole side tank halves secured directlyto each other in a plane extending sub stantially through the axes ofthe terminal bushings, each tank half being dished with a rounded bottomand with sides generally parallel to each other and with an open top sothat when viewed in side elevation perpendicularly to said plane theentire sides of the tank are generally vertical and generally parallelto each other, and horizontal sections taken through the tank being ofoval shape.

9. A circuit interrupter tank having a pair of terminal bushingsextending into the upper end thereof, said terminal bushings divergingaway from each other in upward direction, the lower ends of the terminalbushings extending interiorly within the tank adjacent the mid-portionthereof, arc-extinguishing means associated with the interior ends ofthe terminal bushings, the bottom of the tank being rounded when viewed(in elevation perpendicularly to the plane extending through the axes ofthe terminal bushings and the thereof having a width adjacent the topthereof as great as the idth adjacent the mid-portion thereof, andhorizontal sections taken through the tank being of oval shape with themajor axes of the ovals being substantially in said plane.

10. A liquid break circuit interrupter including an upstanding tank atleast partially filled with an arc extinguishing liquid, an oval headfor the tank having a pair of flat surfaces disposed at an anglerelative to each other, a pair of terminal bushings extending into theupper end of said tank each terminal bushing supported perpendicularlyto one of said flat surfaces, said terminal bushings diverging away fromeach other in an upward direction, the lower ends of the terminalbushings converging toward each other within the tank and extendingadjacent the mid-portion thereof, an arc extinguishing unit associatedwith the interior end of each terminal bushing, a conducting cross-barelectrically interconnecting the arc extinguishing units and adapted toeffect the actuation thereof, the bottom of the tank being rounded whenviewed in side elevation perpendicularly to the plane extending throughthe axes of the terminal bushings and the sides thereof having a widthadjacent the top thereof as great as the width adjacent the midportionthereof, said conducting cross-bar being movable substantially in saidplane, and horizontal sections taken through the tank being of ovalshape with the major axes of the ovals being substantially in said planewithin which the conducting cross-bar moves.

11. A circuit interrupter tank having a pair of terminal bushingsextending into the upper end thereof,

said terminal bushings diverging away from each other in an upwarddirection, the lower ends of the terminal bushings extending interiorlywithin the tank adjacent the mid-portion thereof, arc-extinguishingmeans associated with the interior ends of the terminal bushings, saidtank including a pair of cooperating whole side tank halves secureddirectly to each other in a plane extending substantially through theaxes of the terminal bushings, the bottom of the tank being rounded whenviewed in side elevation perpendicularly to said plane and the sidesthereof having a width adjacent the top thereof as great as the widthadjacent the mid-portion thereof, and

7 8 horizontal sections taken through the tank being of oval 2,126,997Kramer Aug. 16, 1938 shape with the major axes of the ovals beingsubstan- 2,228,232 Hilliard Jan. 7, 1941 tially in said plane. v 72,259,300 Dyer Oct. 14, 1941 References Cited in the file of this patent5 2693519 Baker et a1 1954 UNITED STATES PATENTS FOREIGN PATENTS1,958,421 Daniels May 15, 1934 626,198 Great Britain July 11, 1949

